Intracranial and Hemodynamic Changes after Succinylcholine Administration in Cats. By Cottrell JE, Hartung J, Giffin JP, and Shwiry B. Anesthesia & Analgesia 1983; 62:1006-9. Reprinted with permission.Bolus injections of succinylcholine (1.5 mg/kg) significantly increased intracranial pressure (ICP) in cats under normal conditions from control levels of 8 +/- 1 mmHg to 16 +/- 3 mmHg (+/- SEM, P less than 0.01), and in the presence of artificially increased ICP from control levels of 27 +/- 1 mmHg to 47 +/- 4 mmHg (P less than 0.01). These approximately 100% increases in ICP were accompanied by a transitory decrease in mean arterial pressure (approximately 10 s), followed by a 15 to 20% increase (P less than 0.05). Pulmonary arterial pressure increased 20 to 30% (P less than 0.05). These results, when considered in conjunction with results previously obtained in humans, suggest that succinylcholine may be contraindicated in neurosurgical patients.